A notable feature of this century has been the introduction of medical science to large, undeveloped areas throughout the world. Backward, mainly tropical, regions have become fertile fields for study, particularly of nutritional and parasitic disorders, and the application of the modern biochemical methods have show that many inhabitants of these countries lack certain of the biochemical "normal" values seen in Europeans. One of the most striking differences is that of the serum proteins. Although by no means confined to this continent, these differences are commonly found in Africans.

Magister Scientiae (Medical Bioscience) - MSc(MBS) / The aim of this study is to be the first to ascertain the effects of silver nanoparticles on testosterone production. The Ag NPs used for this study have the following characteristics; purity ≥ 99.5%; 66.7 % of particles have a diameter between 20-40 nm in aqueous solution. Three month old male Balb/C mice were sacrificed and testicular cell cultures were prepared. The cells were subsequently treated with various concentrations of Ag NPs (with or without luteinizing hormone (LH)-treatment) and incubated for 4 hours. Testosterone secretion in the culture supernantant was then determined using a testosterone ELISA kit. Ag NPs (at 20 μg/ml) significantly (p < 0.001) decreased LH-stimulated testosterone production as compared to the control. This study showed that Ag NPs adversely affect testosterone synthesis in vitro and can therefore pose a risk for male reproduction.

Proteins represent major constituent of the extracellular matrix which plays an important role in the formation, maintenance and remodeling of tissues, this project focuses on adsorption of two specific serum proteins fibronectin (FN) and vitronectin (VTN) responsible for mediating cell matrix interaction through integrin binding, tripeptide Arg-Gly-Asp (RGD) sequence found in these protein features are recognized by αβV3 integrin which ultimately helps in clot formation.

In this thesis interactions in complex fluids, such as serum and meat juice, were analysed with optical biosensor techniques. Panels of lectins immobilised on gold surfaces were used for investigation of differences in protein glycosylation pattern in sera and meat juices between various species. The present panel was also used for investigation of global glycosylation changes of serum proteins in type 1 diabetes patients. Biorecognition was evaluated with null ellipsometry and scanning ellipsometry combined with multivariate data analysis techniques (MVDA). Principal component analysis (PCA) showed that the lectin panel enabled discrimination between sera from the different species as well as for the different meat juices. The results also indicate that there is a measurable global alteration in glycosylation pattern of serum proteins in type 1 diabetic patients compared to healthy subjects. Using an artificial neuronal net (ANN), it was also possible to correctly categorise unknown serum samples into their respective class or group. The analytical potential of combining information from lectin panels with multivariate data analysis was thereby demonstrated. Also, a sensitive and specific method based on surface plasmon resonance (SPR) for detection of insulin autoantibodies (IAA) in serum samples from individuals at high risk of developing type 1 diabetes (T1D) has been developed. When measuring trace molecules, such as autoantibodies, in undiluted sera with label-free techniques like SPR, non-specific adsorption of matrix proteins to the sensor surface is often a problem, since it causes a signal that masks the analyte response. The developed method is an indirect competitive immunoassay designed to overcome these problems. Today, IAA is mainly measured in radio immunoassays (RIAs), which are time consuming and require radioactively labelled antigen. With our SPR-based immunoassay the overall assay time is reduced by a factor of &gt;100 (from 4 days to 50 min), while sensitivity is maintained at a level comparable to that offered by RIA. Finally, the assay was used in a screening study of newly diagnosed type 1 diabetes patients and non-diabetic subjects.

Nanoparticles are promising platforms for biomedical applications ranging from diagnostic tools to therapeutic delivery agents. During the course of these applications, nanoparticles are exposed to a complex mixture of extracellular serum proteins that nonspecifically adsorb onto the surface. The resulting protein layer, or protein "corona," creates an interface between nanoparticles and the biological environment. Protecting the nanoparticle surface can reduce protein adsorption, but complete inhibition remains a challenge. As a result, the corona, rather than the nanoparticle itself, mediates the cellular response to the nanoparticle. The following dissertation describes the fundamental characterization of the cellular binding of charged nanoparticles, interactions of protein-nanoparticle complexes with cellular receptors, and the structural and thermodynamic properties of adsorbed corona proteins.

Objetivos: O objetivo do presente estudo foi avaliar a dosagem da transferrina e pré-albumina séricas como marcadoras da resposta ao suporte nutricional em pacientes com câncer de esôfago. Métodos: Estudo clínico não-controlado com 45 pacientes internados com câncer de esôfago submetidos ao suporte nutricional antes de iniciar a terapia oncológica. De acordo com o estado nutricional, os pacientes receberam dieta por sonda nasoentérica, via oral ou combinada (via oral e sonda nasoentérica). O gasto energético basal foi estimado pela equação de Harris-Benedict. Pré-albumina e transferrina séricas foram dosadas antes e após o suporte nutricional. Valores de p < 0,05 foram considerados estatisticamente significativos. Resultados: A média do tempo de suporte nutricional foi de quatorze dias (±4,72). Houve aumento significativo dos níveis séricos de transferrina (p<0,001) e pré-albumina (p=0,002) após suporte nutricional. Aumento dos níveis de transferrina esteve associado com ingestão calórica (p=0,034), ao contrário dos níveis de préalbumina (p=0,864). Não houve relação estatisticamente significativa entre a ingestão de proteína com a variação dos níveis de transferrina (p=0,243) e préalbumina (p=0,913) do pré para o pós-suporte nutricional. Perda de peso na internação se correlacionou significativamente com os níveis de pré-albumina (- 0,545;p<0,001) e transferrina (r=-0,347;p=0,021). Houve associação estatisticamente significativa entre as variações da transferrina e pré-albumina do pré para o póssuporte nutricional (r=0,568; p<0,001). Conclusões: Houve um aumento significativo dos níveis séricos de préalbumina e transferrina após o suporte nutricional. Foi encontrada uma associação estatisticamente significativa entre as variações da transferrina e pré-albumina do pré para o pós-suporte nutricional. / Objectives: This study evaluated serum transferrin and prealbumin levels as markers of response to nutritional support in patients with esophageal cancer. Methods: Clinical, uncontrolled study with 45 hospitalized patients with esophageal cancer who received preoperative nutritional support. According to their nutritional status, patients received nasoenteric tube feeding, an oral diet, or a combined diet (oral and nasoenteric tube feeding. Resting energy expenditure were calculated using the Harris-Benedict equation. Serum prealbumin and transferrin levels were measured before and after nutritional support. P< 0.05 was considered statistically significant. Results: The mean nutritional support duration was 14 (±4.72) days. There was a significant increase in serum transferrin (P<0.001) and prealbumin (P=0.002) levels after nutritional support. The increase in transferrin levels (P=0.034), but not in prealbumin levels (P=0.861), was associated with calorie intake. There was no statistically significant difference between protein intake and variations in the levels of transferrin (P=0.243) and prealbumin (P=0.913) from pre- to post-nutritional support. Weight loss at admission was significantly associated with levels of prealbumin (r=- 0.545; P<0.001) and transferrin (r=-0.347; P=0.021). There was a statistically significant association between transferrin and prealbumin variations from pre- to post-nutritional support (r=0.568; P<0.001). Conclusions: There was a significant increase in serum transferrin and prealbumin levels after nutritional support. A significant association was found between serum transferrin and prealbumin variations.

Objetivos: O objetivo do presente estudo foi avaliar a dosagem da transferrina e pré-albumina séricas como marcadoras da resposta ao suporte nutricional em pacientes com câncer de esôfago. Métodos: Estudo clínico não-controlado com 45 pacientes internados com câncer de esôfago submetidos ao suporte nutricional antes de iniciar a terapia oncológica. De acordo com o estado nutricional, os pacientes receberam dieta por sonda nasoentérica, via oral ou combinada (via oral e sonda nasoentérica). O gasto energético basal foi estimado pela equação de Harris-Benedict. Pré-albumina e transferrina séricas foram dosadas antes e após o suporte nutricional. Valores de p < 0,05 foram considerados estatisticamente significativos. Resultados: A média do tempo de suporte nutricional foi de quatorze dias (±4,72). Houve aumento significativo dos níveis séricos de transferrina (p<0,001) e pré-albumina (p=0,002) após suporte nutricional. Aumento dos níveis de transferrina esteve associado com ingestão calórica (p=0,034), ao contrário dos níveis de préalbumina (p=0,864). Não houve relação estatisticamente significativa entre a ingestão de proteína com a variação dos níveis de transferrina (p=0,243) e préalbumina (p=0,913) do pré para o pós-suporte nutricional. Perda de peso na internação se correlacionou significativamente com os níveis de pré-albumina (- 0,545;p<0,001) e transferrina (r=-0,347;p=0,021). Houve associação estatisticamente significativa entre as variações da transferrina e pré-albumina do pré para o póssuporte nutricional (r=0,568; p<0,001). Conclusões: Houve um aumento significativo dos níveis séricos de préalbumina e transferrina após o suporte nutricional. Foi encontrada uma associação estatisticamente significativa entre as variações da transferrina e pré-albumina do pré para o pós-suporte nutricional. / Objectives: This study evaluated serum transferrin and prealbumin levels as markers of response to nutritional support in patients with esophageal cancer. Methods: Clinical, uncontrolled study with 45 hospitalized patients with esophageal cancer who received preoperative nutritional support. According to their nutritional status, patients received nasoenteric tube feeding, an oral diet, or a combined diet (oral and nasoenteric tube feeding. Resting energy expenditure were calculated using the Harris-Benedict equation. Serum prealbumin and transferrin levels were measured before and after nutritional support. P< 0.05 was considered statistically significant. Results: The mean nutritional support duration was 14 (±4.72) days. There was a significant increase in serum transferrin (P<0.001) and prealbumin (P=0.002) levels after nutritional support. The increase in transferrin levels (P=0.034), but not in prealbumin levels (P=0.861), was associated with calorie intake. There was no statistically significant difference between protein intake and variations in the levels of transferrin (P=0.243) and prealbumin (P=0.913) from pre- to post-nutritional support. Weight loss at admission was significantly associated with levels of prealbumin (r=- 0.545; P<0.001) and transferrin (r=-0.347; P=0.021). There was a statistically significant association between transferrin and prealbumin variations from pre- to post-nutritional support (r=0.568; P<0.001). Conclusions: There was a significant increase in serum transferrin and prealbumin levels after nutritional support. A significant association was found between serum transferrin and prealbumin variations.

This study aimed to evaluate the oxidative status and electrophoresis of sheep experimentally infected with Haemonchus contortus and supplemented with selenium and copper. We used 28 Corriedale and Texel crossbred lambs were divided into four groups with seven animals each: G1 consisted of animals infected with larvae of G2 were infected with larvae in lambs supplemented with 0.2 mg / kg body weight (LW) of sodium selenite intramuscular (IM), G3 were infected with larvae and supplemented with 3.5 mg / kg BW of copper by subcutaneous (SC); G4 consisted of animals infected with larvae and supplemented with 0.2 mg / kg BW IM sodium selenite and 3.5 mg / kg LW SC copper. All groups were infected orally with 500 L3 larvae of Haemonchus contortus per animal every other day for a period of twenty days from the day zero. The blood samples used for biochemical analysis were collected on days zero (T0), 20 (T1), 40 (T2), 60 (T3) and 80 (T4) by jugular venipuncture using vacutainer tubes®. Weights and determination of eggs per gram of feces of animals occurred in these experimental times. The gradual increase in catalase and TBARS values in all groups showed oxidative stress and inflammation due to parasitic infection. There was an increased activity of GSH-Px in G2 at T0, T1 and T4 as compared to G1 and T4 when compared with G3. Selenium supplementation promoted a greater antioxidant activity in parasitized animals. The use of copper caused an increase in weight gain of experimental animals. The use of sodium selenite associated with copper was more effective in increasing levels of total protein, albumin and gamma globulin in T4, which were also obtained the lowest FEC and worm burden. / O presente trabalho teve como objetivo avaliar o perfil oxidativo e de proteínas séricas de cordeiros experimentalmente infectados com Haemonchus contortus e suplementados com selênio e cobre. Foram utilizados 28 cordeiros mestiços Corriedale e Texel, alocados em quatro grupos experimentais com sete animais cada: G1-animais infectados; G2-infectados e suplementados com 0,2 mg/kg de peso vivo (PV) de selenito de sódio por via intramuscular (IM); G3-infectados e suplementados com 3,5 mg/kg PV de cobre por via sub-cutânea (SC); G4-infectados e suplementados com 0,2 mg/kg PV de selenito de sódio IM e 3,5 mg/kg PV de cobre SC. A infecção foi realizada por via oral, com 500 larvas L3 de Haemonchus contortus por animal a cada dois dias, durante vinte dias a partir do dia zero. As amostras sanguíneas utilizadas para as análises bioquímicas foram coletadas nos dias zero (T0), 20 (T1), 40 (T2), 60 (T3) e 80 (T4) por venopunção da jugular utilizando-se tubos vacutainer®. Nestes mesmos períodos foram realizadas pesagens e a determinação dos ovos por grama de fezes dos animais. O aumento gradativo nos valores de TBARS e catalase em todos os grupos demonstrou estresse oxidativo e processo inflamatório em decorrência da parasitose. Houve um aumento na atividade da GSH-Px nos cordeiros suplementados com selênio no T0, T1 e T4 em relação ao grupo controle e no T4 quando comparado com o G3. A suplementação com o selênio promoveu uma maior ação antioxidante nos animais parasitados. O uso do cobre causou um incremento no ganho de peso dos animais experimentais. A utilização de selenito de sódio associado ao cobre demonstrou maior eficácia em aumentar os níveis de proteínas totais, albumina e gamaglobulina nos ovinos ao final do experimento (T4), quando também foram obtidos os menores valores de OPG e carga parasitária.

Objetivos: O objetivo do presente estudo foi avaliar a dosagem da transferrina e pré-albumina séricas como marcadoras da resposta ao suporte nutricional em pacientes com câncer de esôfago. Métodos: Estudo clínico não-controlado com 45 pacientes internados com câncer de esôfago submetidos ao suporte nutricional antes de iniciar a terapia oncológica. De acordo com o estado nutricional, os pacientes receberam dieta por sonda nasoentérica, via oral ou combinada (via oral e sonda nasoentérica). O gasto energético basal foi estimado pela equação de Harris-Benedict. Pré-albumina e transferrina séricas foram dosadas antes e após o suporte nutricional. Valores de p < 0,05 foram considerados estatisticamente significativos. Resultados: A média do tempo de suporte nutricional foi de quatorze dias (±4,72). Houve aumento significativo dos níveis séricos de transferrina (p<0,001) e pré-albumina (p=0,002) após suporte nutricional. Aumento dos níveis de transferrina esteve associado com ingestão calórica (p=0,034), ao contrário dos níveis de préalbumina (p=0,864). Não houve relação estatisticamente significativa entre a ingestão de proteína com a variação dos níveis de transferrina (p=0,243) e préalbumina (p=0,913) do pré para o pós-suporte nutricional. Perda de peso na internação se correlacionou significativamente com os níveis de pré-albumina (- 0,545;p<0,001) e transferrina (r=-0,347;p=0,021). Houve associação estatisticamente significativa entre as variações da transferrina e pré-albumina do pré para o póssuporte nutricional (r=0,568; p<0,001). Conclusões: Houve um aumento significativo dos níveis séricos de préalbumina e transferrina após o suporte nutricional. Foi encontrada uma associação estatisticamente significativa entre as variações da transferrina e pré-albumina do pré para o pós-suporte nutricional. / Objectives: This study evaluated serum transferrin and prealbumin levels as markers of response to nutritional support in patients with esophageal cancer. Methods: Clinical, uncontrolled study with 45 hospitalized patients with esophageal cancer who received preoperative nutritional support. According to their nutritional status, patients received nasoenteric tube feeding, an oral diet, or a combined diet (oral and nasoenteric tube feeding. Resting energy expenditure were calculated using the Harris-Benedict equation. Serum prealbumin and transferrin levels were measured before and after nutritional support. P< 0.05 was considered statistically significant. Results: The mean nutritional support duration was 14 (±4.72) days. There was a significant increase in serum transferrin (P<0.001) and prealbumin (P=0.002) levels after nutritional support. The increase in transferrin levels (P=0.034), but not in prealbumin levels (P=0.861), was associated with calorie intake. There was no statistically significant difference between protein intake and variations in the levels of transferrin (P=0.243) and prealbumin (P=0.913) from pre- to post-nutritional support. Weight loss at admission was significantly associated with levels of prealbumin (r=- 0.545; P<0.001) and transferrin (r=-0.347; P=0.021). There was a statistically significant association between transferrin and prealbumin variations from pre- to post-nutritional support (r=0.568; P<0.001). Conclusions: There was a significant increase in serum transferrin and prealbumin levels after nutritional support. A significant association was found between serum transferrin and prealbumin variations.

1. For the first time a wide range of biochemical genetic markers and different typing techniques were used to access levels of genetic variability in Lithuanian horse breeds; 2. DNA based methods were used to access levels of genetic variation in Lithuanian horse breeds; 3. Genetic variation in Lithuanian horses was investigated using mitochondrial DNA (mtDNA) sequencing; 4. Genetic relationship and genetic distances between the breeds were estimated using a wide range of different genetic markers.